What is the most child friendly dog breed?

I’m looking for a dog that would fit my 2 year old boy. I know that all dogs need proper social integration and all, but in general I am looking for a breed that is known to be both tolerant and non-aggressive.

I don’t really care about size, but I work a lot, so it would be very helpful with a dog that is not big size, as others will have to go for a walk / watch it for me as well.

A plus would also be a breed with few genetic health issues and that can get along with other dogs.